7 Subaru EZ36 3.6L Engine Problems You Need To Know About

Subaru Tribeca, Legacy and Outbacks, made between 2010 and 2019, were commonly equipped with Subaru’s incredible EZ36 3.6L engine. With its 6-cylinder boxer engine, the power output and engine sound were both impressive. But is the EZ36 a reliable choice? That’s why we’re here for.

Doing good and thorough research beforehand is always a good idea. You just don’t want to end up with a car with an unreliable engine that will drain your wallet. You need something good that will endure in the foreseeable future. And this is why we are here to help you out and pinpoint these issues for you.

First, we are going to learn more about the specs of the EZ36 engine. Then, we are going to cover the common Subaru EZ36 3.6L engine problems and also the applications of this engine. So, without further ado, let’s dive into the article.

Basic Subaru EZ36 3.6L Engine Specs

The EZ36 engine is an engine that was produced by Subaru between 2007 and 2019. This engine shares the core design with the smaller EZ30.

The main difference between the two is the displacement and power they create. Except for that, the EZ36 uses thinner sleeves in order to increase the bore. These similarities mean that they also share a lot of the problems. But more on the problems later on.

What is interesting to note about the EZ family of engines is that these engines are six-cylinder boxer engines. Subaru simply loves this engine design and is very persistent in using it and refining the boxer layout over the years.

What is also worth noting is that the EZ36 implements asymmetric rods that allow an increase in displacement. The engine also implements dual variable valve timing but does not have a variable valve lift.

Also, the exhaust manifolds were redesigned for the EZ36 along with the cooling system.

This engine layout sits pretty low in the engine bay, which means that the center of gravity is also low and the cars with these boxer engines handle pretty well.

Especially the EZ36, which is probably the highest-displacement boxer engine that Subaru ever introduced to the market.

The specs of the EZ36 are the following:

  • Configuration: 6 Cylinder Boxer
  • Displacement: 3.6L
  • Cylinder Bore: 92 mm
  • Piston Stroke: 91 mm
  • Block & Head Material: Aluminum
  • Head Design: DOHC, 4 valves per cylinder
  • Compression Ratio: 10.5
  • Aspiration: Naturally Aspirated
  • Horsepower: 260 hp
  • Torque Output: 247 lb-ft (335 N-m)

Common Subaru EZ36 3.6L Engine Problems

Here is a list of common problems with the EZ36 engine:

  • Serpentine Belt Tensioner
  • Timing Chain Tensioner
  • Overheating
  • Oil Leaks
  • Blown Head Gasket
  • High Fuel Consumption
  • AC Compressor Failure

We listed the common Subaru EZ36 3.6L engine problems, now let’s move on and learn more about these problems one by one.

Knowing how and when these issues occur is really important in order to understand the problem. Many people do not understand these issues, this is why we need to elaborate on them in depth.

Serpentine Belt Tensioner

The first problem on our list of Subaru EZ36 3.6L engine problems is the serpentine belt tensioner. So, what is a serpentine belt tensioner?

A serpentine belt tensioner is a device that is intended to apply pressure on the serpentine belt. So, the serpentine belt does not fall off.

The serpentine belt is the belt that is running the accessories. Such as the alternator and AC. This belt is also known as a drive belt and accessory belt.

So, what happens is that this tensioner over time can become loose and lose the tension. In this case, the belt can start to squeak or completely fall off.

If this happens while you drive the car, the engine might stall and you will lose power since the alternator will not work.

This is why replacing the tensioner is a good idea if you notice squeaks from the belt and if there is a lack of tension.

Timing Chain Tensioner

The next problem on our list of Subaru EZ36 3.6L engine problems is the timing chain tensioner. So, this is another tensioner.

But this tensioner is intended for the timing chain. The timing chain is buried deep behind the timing cover and is impossible to make a visual inspection of it unless you remove the timing cover. This will require complete front end or engine removal in many cases.

What can happen is that with the increase in mileage, the tensioner will start to lose its properties and allow the chain to wobble.

When this happens, you have a timing chain rattle. And this is the key, if you notice that something is rattling behind the timing cover, you have to react quickly. Because if you don’t, the engine can fail.

Pistons and valves will collide and there will be carnage inside the engine. In many cases, the repair is more expensive than a new engine. So, you get the idea. That’s why, beware of rattling noises coming from the timing covers.


Overheating is another big issue with the Subaru EZ36 engine. And honestly, this issue is present on a lot of Subaru engines, especially the H4 boxers.

But fortunately, the bigger EZ engines do not suffer a lot from these issues. Still, this doesn’t mean that these issues cannot appear.

Many people say that this is happening because of the insufficient cooling that the cooling system delivers on the EZ36 and advise that you go for an aftermarket radiator with a bigger capacity to cool off the engine better.

And we honestly, agree with this, if you want to bulletproof your EZ36 engine, going for an aftermarket solution might be a good idea in order to not deal with overheating issues in the future.

Now let’s move on to the next Subaru EZ36 3.6L engine problems.

Oil Leaks

Oil leaks are another common problem with this engine. What is worth noting is that every Subaru engine is plagued with these issues.

There are exceptions but these are probably really low mileage engines or engines that have been well taken care of during their life.

And these oil leaks can come from anywhere, they can come from the timing covers, oil pan, and valve covers.

Subaru gaskets are not quite good. Even so, the EZ engine series has probably better quality gaskets than the regular EJ and FB four-cylinder engines.

Still, there are leaks and these leaks need to be properly addressed in order for you to avoid engine damage because you lose oil all the time.

Blown Head Gasket

Blown head gaskets are another big headache for Subaru engines and the EZ36 is not an exception to this rule.

They might rarely happen compared to other engines in the Subaru lineup but they do happen and when they happen, they are really expensive to fix.

The head gasket tends to fail once the car overheats. This gasket is located between the cylinder head and the deck of the block.

On this specific engine you have two of these gaskets and when they fail can often require removal of the engine and a lot of money to get fixed. This is the case because the cylinder head has to be resurfaced and refinished. So, it’s a pretty laborious and time-intensive job.

High Fuel Consumption

Another on our list of Subaru EZ36 3.6L engine problems is not a proper problem but more of a downside of this engine.

The engine itself is not very efficient. Its fuel economy can be somewhat worse than an alternative 3.6 V6 engine.

And with prices of gas rising pretty high nowadays, you should definitely beware of this because it might cost you a good penny to fill up that tank.

AC Compressor Failure

And last but not least is the AC compressor failure. This is also not an engine problem but an accessory problem.

Still, the AC is connected to the engine and the engine gives power to this compressor. These compressors are not one of the best out there.

The unit itself can fail as well as the O-rings of the compressor that can fail on these EZ engines.

Which Subaru’s have the EZ36 3.6L Engine?

Now let’s see which models have the EZ36 3.6L engine.

  • 2008 – 2014 Subaru Tribeca
  • 2010 – 2019 Subaru Legacy
  • 2020 – 2019 Subaru Outback


What Are The Common Subaru EZ36 3.6L Engine Problems?

Common problems with the EZ36 engine include oil leaks, timing chain tensioner failures, serpentine belt tensioner failures, and overheating issues. Overall, this engine does not have serious issues like other Subaru engines do, it is pretty good and durable, and can easily go for 200,000+ miles.

Is the Subaru EZ36 3.6L engine a good engine?

Yes, the EZ36 engine is pretty durable and reliable. It is not perfect but still able to be pushed in the long run. There are no reliability concerns except for its cooling system which can perform somewhat poorly. Other issues can also arise like oil leaks here and there but overall nothing too significant for this engine. The only downside is probably its fuel consumption. The EZ36 is a thirsty engine that can use a lot of fuel for its displacement.

Is the Subaru EZ36 3.6L engine a boxer?

Yes, the Subaru EZ36 3.6l is a 6-cylinder boxer engine.

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